Smart phones, mobiles phones, and portable payment devices contain therein a financial chip, which is provided for mobile payment by finance companies (for example, card companies or banks), or a Universal Subscriber Identity Module (USIM) chip, to process mobile payment. A USIM chip has payment device holder's personal information (communication service provider information, a user password, roaming information, and a mobile terminal user's phone number) for user authentication, and forms a type of a smart card.
A USIM chip has high security because encryption techniques are applied differently from existing wireless communication methods (for example, Bluetooth, Zigbee, and RFID). Also, identification time at a close range (for example, 10 centimeters) is just 0.1 seconds, and the USIM chip is capable of bidirectional communication. Such aspects are advantageous for mobile payment using a card reader.
However, after a finance company such as a card company or a bank installs a financial application to a USIM chip, it is difficult to additionally install a financial application of another finance company in the same USIM chip. When a first finance company accesses a USIM chip using a first primary key and records card information, the primary key is changed to an issuer key issued by the first finance company. Therefore, it is difficult for another finance company to record additional card information to the USIM chip. In other words, because a USIM chip corresponds to a single finance company, a payment device such as a smart phone or a mobile phone may not use various finance companies. This will be described referring to FIG. 1.
FIG. 1 illustrates a reference drawing of a method for using a conventional USIM chip embedded in a payment device.
Referring to FIG. 1, in the case of a conventional USIM chip, a card company server 25 obtains a primary key (KEY 1) that has been set for the USIM chip, and accesses a storage area in the USIM chip using the primary key (KEY 1). The card company server 25 accesses the storage area and installs an application for financial transactions. When the application is installed, the card company server changes the first set primary key (KEY 1) to an issuer key (KEY 2). Because the issuer key (KEY 2) is not disclosed to other card companies, access to the USIM chip by servers of other card companies may be limited. In other words, a USIM chip mounted in a payment device is occupied by a single card company server 25, and a payment means of the payment device is limited by the card information provided by the corresponding card company server 25. To solve this problem, a separate smart chip shareable by multiple card companies or a smart card may be additionally mounted in the payment device. However, this may create an additional burden for the payment device. Furthermore, the usefulness of the USIM chip that is basically mounted in smart phones or mobile phones may be reduced.